Lithium-ion battery diagnostic and prognostic techniques

United States Patent

Embodiments provide a method and a system for determining cell imbalance condition of a multi-cell battery including a plurality of cell strings. To determine a cell imbalance condition, a charge current is applied to the battery and is monitored during charging. The charging time for each cell string is determined based on the monitor of the charge current. A charge time difference of any two cell strings in the battery is used to determine the cell imbalance condition by comparing with a predetermined acceptable charge time difference for the cell strings.

GOVERNMENT RIGHTS
This invention was made with government support under Contract No. DAAD19-01-2-00100 awarded by the United States Army Research Laboratory to the Power and Energy Consortium. The government may have certain rights in the invention.